FEELER: API style console (Toft ATB complete rebuild)

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r2d2

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So cool project
any info about cost of complete single channel (parts only) and complete master section ?
cheers
 

Floti

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Hi!

With CAPI transformers and GAR Opamps it would cost around (but not more than) 300€ per channel in case you are bulding just one channel. If you are building 16 and buy everything at the same time you can reduce the costs significantly, for example, it costs about 2 € to buy 9 resistors at mouser, but 4 € to buy 200!
 

myers1st

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Just got my boards, 4 inputs and a pair of subgroups, they look great! Looking forward to getting starred.  Anybody else finish any of these yet?
 

qmp audio

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Hello Floti,  how is your build going?  Did you ever create a master module and/or group modules?  i'd be interested in getting some of those,  especially the master,  if so.
 

Floti

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me too!!

sorry guys, it´s actually almost done, but I´m finishing my band´s record right now and haven´t got the time! During christmast holiday I should be able to finish that. That´s the plan.

Best!
 

Indecline

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Awesome project!.. and quite ridiculous in the best possibly way  ;D

I’d love to see the sub/master modules.. it’d be really tempting to grab a toft and hit the whole thing at that point!
 

ruffrecords

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Floti said:
The finished board

This is a very interesting design. If I may I have a couple of questions about its construction.

1. What is the width of a module? I am guessing 40mm
2. Do you anticipate any crosstalk between the output transformers in adjacent modules.?I take it there is no screening between modules.

Cheers

ian
 

myers1st

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I'm just waiting for CAPI transformers to show up on Tuesday to finish my first input module to test.  If it works fine, I'll finish my other three input boards and can do some crosstalk measurements.

Also, if you're cheap like me and you don't care about saving your old Toft input cards, you can remove and reuse the pushbutton switches and save about $30 per channel.  Can't salvage the pots though. 

Anyone else finish an input board? 
 

jawilkes84

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Dec 15, 2018
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I have 8 input modules to build. Do let us know about the crosstalk.
Anyone able to get hold of Floti? he doesn't seem to be replying to emails. Can't blame him to be honest with the current state of affairs.
 

myers1st

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So I finally finished one input module, but there is an issue with the alignment of the pots with the Bourns 901/902, the distance from the PCB to center of shaft is too small so that they don’t line up with the holes in the console faceplates. 

A warning to anyone starting to build these:
Unfortunately I didn’t check this before soldering the switches on the other side of the PCB so it’s impossible to remove the pots without removing the switches.  Without a good desoldering station, I’m gonna shred traces, so I’m basically going to waste this board and just start a new one and save as many components as I can.

I can’t find pots with the footprint in the PCB with the right height, so I think I will use a short bit of ribbon cable to bring the pots off the PCB and push them in through the faceplate one by one.
 

qmp audio

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myers1st said:
So I finally finished one input module, but there is an issue with the alignment of the pots with the Bourns 901/902, the distance from the PCB to center of shaft is too small so that they don’t line up with the holes in the console faceplates. 

Here some some notes i had saved in my docs about the pots, if it is helpful to anyone:

- Solder the pots before you solder the switches or you won‘t be able to. Also check with a channel the height at which you need to solder the pots. I found I needed to solder them so that the legs are just in the solder holes.
- The pot that is not well placed in the pcb is the channel pan pot. Soldee it with wire and screw it to the panel.
- The Gain pot has a screw part that is too wide. You need to solder it so that the plastic thing comes out the panel or just use another pot.
 

Floti

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Hi! Glad to see people building these! Also James (jawilkes) is pretty active these days, we´ve been sharing info through email.

Well, there have been some revisions to the pcbs, so I´d need to check which one you have to answer all the questions.

I don´t know if I wrote it to you at the time you got the pcbs or not, but to some People I did for sure recommend to:

1. Solder the pots before you solder the switches
2. Try to solder the pots so that the legs are in the holes but don´t come through. I found that doing so the shaft comes through the hole in the faceplate. You can build the pcbs next to an original channel to check for height and adjust, but my channels come through, that´s for sure!

In the last revision of the input channels I opted for a grayhill switch instead of a gain pot. I love being able to recall gain and the switch comes through the faceplate just fine.

Also the note about the pan pot being wrong placed is true for an older revision, not the final one.

Sorry about the inconvenience, let me know if you need a new pcb and I´ll be happy to send it your way. 
 

Floti

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qmp audio said:
Hello Floti,  how is your build going?  Did you ever create a master module and/or group modules?  i'd be interested in getting some of those,  especially the master,  if so.

jawilkes84 is soldering a group module right now, He will use it as a master bus replacement since his master bus was failing. If there´s no major problems I can order some and offer you dose too. I plan on building/testing one soon. The master channel, in a simplified version (no headphone amp, no talkback) is almost done, as has been the case for a Long time. It´s just that I need to find the time to do the final touches and get it fabricated and so on. I´m positive that I will have everything done this year.
 

myers1st

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Sep 12, 2017
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Hey Floti!!!  Good to hear from you, and great news about the master module.  I was planning the same thing to use a pair of submasters as my mix bus for now.

Sorry, I must have missed that note about soldering the pots in raised off the pcb.  I put pots in first, but once I put the switches on, I couldn't access the pots to raise them up.  I took the switches off, but tore a bunch of traces, so I'll just start fresh with a new board.  Oh well, live and learn.  Will report back when I  finish one and test it out!

Do you have any more input boards available? 
 

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